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(11) |
EP 0 811 800 A1 |
| (12) |
EUROPEAN PATENT APPLICATION |
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Date of publication: |
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10.12.1997 Bulletin 1997/50 |
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Date of filing: 26.09.1996 |
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Designated Contracting States: |
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AT CH DE ES FR LI |
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Priority: |
06.06.1996 IT MI960424 U
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Applicant: Gigi Molina - Brevetti Plastici S.p.A. |
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Romentino (Novara) (IT) |
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| (72) |
Inventor: |
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- Molina, Luigi
28100 Novara (IT)
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| (74) |
Representative: Mercurio, Franco et al |
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c/o Società Italiana Brevetti S.p.A.
Via Carducci, 8 20123 Milano 20123 Milano (IT) |
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| (54) |
Mechanically tightening joint for connection to a main pipe |
(57) A mechanically tightening joint for connection to a main pipe (10) in which the latter
presents on its surface a through aperture (11) to which said joint (12) is to be
applied, said joint being provided with an aperture (13) to be coupled to aperture
(11) of the main pipe (10), wherein the joint (12) is provided with mechanically tightening
means (17) that can be operated from the outside of joint (12) and are suitable to
secure the joint (12) and the main pipe (10) to one another.
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[0001] The present invention relates to a mechanically tightening joint for connection to
a main pipe, said joints being expecially suited for connection to sewage piping or
for branching on industrial plants.
[0002] Joints with the following technical characteristics for connection to main or basis
pipes are known:
- onto PVC pipings, which material belongs to the class of thermoplastic materials and
can therefore be modified with the aid of a heat source, a hole used to be drilled
on the main pipe, with heat a properly sized cuff for the inlet tube to be connected
was formed, and the basis cuff was finally welded to the joint, both tubes being obviously
of the same or a similar material in this case PVC.
- a simpler method was thereafter adopted, the so called saddle joint, with the creation
of a pipe length covering more than half of the diameter of the base pipe and having
the joint welded thereon or obtained by moulding withouth welding. In such a method
it was enough to drill a hole in the main pipe and to fit the piece thereon as a whole
in such a way that the same by reaching beyond halfway of the pipe would be in engagement
relationship with the base pipe. In such a case, the feature of the material of the
two pipes is that it should be the same for a welding or sticking between the saddle
joint and the basis conduit to possibly occur. This normally occurs with PVC pipes.
- Still referring to the prior art, pipes of HDPE or polypropylene, where adhesive bonding
is absolutely impossible, it was, and still is, necessary to use the welding system.
It is to be noted that in the field of sewage systems HDPE and polypropylene are much
less used than PVC.
- With stiff piping, such as ceramic stoneware, asbestos cement, prestressed concrete
and similar pipes, a hole is drilled in the main pipe wherein the joint is fitted
with the aid of a rubber gasket in order to possibly assure a perfect seal.
- For pipings made of spheroidal graphite cast iron or steel the main problem is drilling
the hole in the pipe, steel at least allowing welding to be carried out whilst for
the spheroidal graphite cast iron the only possible aid consists of more or less effective
gaskets.
[0003] The above-mentioned joints used up to now have the draw-backs of requiring complicated
expensive techniques, skilled personnel and considerable investiment in the production
of moulds for the various size features of the joints and of the pipes they are to
be connected to, and moreover it is not possible to assure a perfect seal between
the pipes.
[0004] The joint that is the object of the present invention allows the above-mentioned
draw backs to be eliminated, and provides the advantages that will be clearly set
out in the following description of a simplified, non limiting, embodiment, with reference
to the enclosed drawing, in which:
FIGURE 1 is an exploded view of the various parts of the joint and of the main pipe;
FIGURE 2 is a front view of the joint as applied to the main pipe;
FIGURE 3 is a top view of the joint as applied to the main pipe; and
FIGURE 4 is a side view of the joint as applied to the main pipe.
[0005] As can be seen from the figures, the main pipe 10 has a through aperture 11 on its
surface, to which aperture the joint 12 is applied, joint 12 being provided with aperture
13. Said joint 12, that can be arranged at any angle or in any position relative to
the main pipe 10, comprises two blocks 14 that are each provided with a through-hole
15 through which a threaded pin 16 is placed, said pin being provided with mechanically
tightening means 17 that are suited to secure the joint 12 to the main pipe 10. The
number of said blocks might be higher than two, according to the dimensions of the
joint and of the main pipe. Between the joint 12 and the main pipe 10 a gasket 18
is interposed, said gasket having a central aperture 19 that is suited to be interposed
between aperture 13 of joint 12 and aperture 11 of the main pipe 10.
[0006] The mechanical tightening means 17 comprise: a tab 20 secured at an end of each of
said threaded pins 16 and a screw nut or double screw nut 21 coupled to the other
end of said pins 16, so that each tab 20 is placed against the inner part of the main
pipe 10 and is suited to tighten the latter against the joint 12 by tightening from
outside the screw nut or double screw nut 21 on pins 16 against the upper part of
said blocks 14.
[0007] Said tightening means is comfortably and easily used because the control screw nut
or double screw nut 21 is arranged in an easily accessible region outside of blocks
14.
[0008] From the above description, the various advantages offered by the joint of the present
invention can easily be seen, and they can be summed up as follows:
it is a universal joint as it can be used whatever material the joint and the main
pipe are made of, it exhibits such features that the best seal between the parts to
be connected is assured and has the advantage of the joint being easily and quickly
disassembled from the main pipe for carrying out repairs.
[0009] Practical construction changes can be made to the invention withouth possibly getting
out of the scope of the present invention as claimed hereinafter.
1. A mechanically tightening joint for connection to a main pipe (10) in which the latter
presents on its surface a through aperture (11) to which said joint (12) is to be
applied, said joint being provided with an aperture (13), characterized in that said
joint (12) comprises two blocks (14) that are each provided with a through-hole (15)
through which a threaded pin (16) is placed, said pin being provided with mechanically
tightening means (17) that are suited to secure said joint (12) to said main pipe
(10).
2. A joint according to claim 1, characterized in that it comprises a seal (18) having
a central aperture (19) that is suited to be interposed between the aperture (13)
of joint (12) and the aperture (11) of the main pipe (10).
3. A joint as claimed in any of the preceding claims, characterized in that the mechanical
tightening means (17) comprise: a tab (20) secured at an end of each of said threaded
pins (16) and a screw nut or double screw nut (21) coupled to the other end of said
pins (16), so that each tab (20) that is arranged against the inner part of the main
pipe (10), is suited to tighten the latter against the joint (12) by tightening from
outside the screw nut or double screw nut (21) on pins (16) against the upper part
of said blocks (14).
4. A joint as claimed in any of the preceeding claims, characterized in that it can be
arranged at any angle or in any position relative to the main pipe.
